1. Field of the Invention
The present invention relates to a sulfur-modified chloroprene rubber, a molding thereof, and a production method therefor. Specifically, it relates to a sulfur-modified chloroprene rubber that is used in dynamic environment applications, such as driving belts and conveyer belts generally used in industries and air springs and anti-vibration rubbers for automobiles, and a molding thereof and a production method therefor.
2. Description of the Related Art
Chloroprene rubbers, which are grouped grossly into sulfur-modified chloroprene rubbers and non-sulfur-modified chloroprene rubbers, are used in a variety of fields, for example as auto parts, adhesive agents, various industrial components and others, using the properties of respective rubbers.
Sulfur-modified chloroprene rubbers with their superior dynamic properties have been used in various dynamic environment applications, for example as driving belts and conveyer belts used generally in industries, air springs and antivibration rubbers for automobiles and others. Because these products deform and return to their original shape repeatedly under dynamic stress, these rubbers themselves generate heat, causing a problem of degradation thereof and reduction of product lifetime. Thus, there exists an urgent need for development of a sulfur-modified chloroprene rubber with reduced exothermicity.
As an example of the method of reducing the exothermicity of rubbers, known is a low-exothermicity rubber composition comprising an elastomer crosslinkable with an organic peroxide-based crosslinking agent such as acrylonitrile-butadiene copolymer rubber, a metal salt of α,β-ethylenic unsaturated carboxylic acid, magnesium oxide having a BET specific surface area of 25 m2/g or less, and an organic peroxide-based crosslinking agent (see Patent Document 1). Also known is a rubber composition containing a particular low-exothermicity carbon black (see Patent Document 2). Also known is a modified conjugated diene-based polymer obtained by mixing a high-molecular weight component (A) having particular properties and a low-molecular weight component (B) having particular properties (see Patent Document 3).